Circuit-breaking relay



`lune 19, 1928.

` N. R. HAAS CIRCUIT BREAKING RELAY Filed April 12. 1922 47 M16/fr Howl/afl? Patented .lune 19, 19.28.. UNITED STATES 1,673,819 PATENT oFFlcE.

NELSON R. HAAS, OF DAYTON, OHIO, ASSIGNOR, BY MESNE `ASSIGNMENTS, TO.DELCO REMY `CORPORATION, OF DAYTON,

OHIO, A CORPORATION OF DELAWARE.

CIRCUIT-BREAKING RELAY.

Application led April 1,2,l 1922. Serial No. 551,893.

This invention` relates to the art of regulating lan electriccurrent to prevent excessive current flow in a circuit, and more especially, to circuit breakers employed in automotive lighting and ignition systems .to prevent damage to the system when a short circuit is formed. The principal objects of the'present invention are to provide an apparatus Whichwill operate efficiently on a relatively small amount of current, and

which will produce a loud sound when there is ashort in the electrical system. In the accompanying drawings:

Fig. l is an end view of an apparatus embodying the present invention mounted on the back of a switch box;

Fig. 2 is a transverse sectional view of the switch box with the circuit breaking relay, shown in side view, mounted thereon;

Fig. 3 .is a side view of the circuitbreaking relayy and showing diagrammatically a part of an electrical circuit connected to the relay l Fig. 4 is a longitudinal sectional view of the circuit breaking relay taken substantial- 1y on the line 4-4 of Fig. 1.

In these drawings 10 is a switch box adapted to be mounted onthe instrument board of an automobile and having a base 3o plate 11 of insulating material, sides 1'2,

face plate 13, a manually operable member 14 controlling a switch or contact bridging member 15, and a plurality of contacts of which but two, numbered 16 and 17 ,are shown in Fig. 2. These contacts are connected to binding posts 18 and 19 respectively. This switcli illustrates one of a number of types of switch constructions which may be employed and it is believed unneces' sary to show the same in greater detail.

Secured to the rear face ofthe base plate 11, is a yoke 20 forming the frame of the circuit` breaking rela -and having parallel arms 21, 22, a centra ly apertured end plate 23 and a lateral fiange 24 on the end of arm 22. Binding post 18 passesthrough a hole 25 in the flange 24 and holds the frame securely against the base of the switch box.

26 is a cylindrical soft iron core having a stepped axial bore and a hollow end boss 27 passing through the central opening in the end plate 23 and riveted to the latter securely holding the core in alignment with arms 21, 22 of the yoke 20. 28 is a cylindrical rod movably mounted in the hollow boss on the outer end of `core and having an enlarged portion 29 slidably mounted in the larger bore of the core and a smaller portion 30 slidably mounted in the smaller bore of the core, this portion of the rod projecting through the hollow boss if 27.- A coiled compression spring 31 encircles the\ reduced portion 30 of the rod and abuts against the enlarged portion 29 and the end wall of the core 26. 32 is an end Surthe rod 28, sup- *i 7b Mounted on the cross arm 23 of the yoke 20 is a hollow disc 39 of insulating materiallseparating a centrally apertured metal plate from the yoke. Plate 4() carries ak fixed hollow contact 41 secured in the open- 30 ing in the plate 40 in alignment with thev rod 28. Spring 42 secured to yoke arm 21 carries on itsffree end a movable contact 43 normally engaging contact 41. Lateral projections 44 on the plate 40 protect the contacts during shipment or handling of the circuit breaking relay.

One end of the coil 35 is connected'by binding post 45 with a battery 46, and the other end of the coil is connected to the metal plate 40 carrying vthe fixed Contact 41. The yoke 20 is electrically connected through binding, post 18 to contact 16 and a wire 46 which may be connected to the horn or other electrical devices on the automobile.

Contacts 17 and 47 may be connected to the head lights and contact 48 to the tail light.

Different materials may be used in the contact operating rod 28 and the disc 33, and 7;

the spacing of the parts maybe varied according to the operation desired. The following is a preferred method of constructing the parts. The size of the circuit breaking relay is substantially one-half that shown in Fig. 4. The rod 28 is made of brass, weighs about 1/8 ounces and the inner end is normally spaced about .040 of an inch from the movable contact 43. The disc 33 is made of soft iron, weighs about 378 ounces,

and its inner face is normally-spaced about .062 of an inch from the outer end of the core, and the Cylindrical surface of the disc is spaced about .02 of an inch from the arms 21, 22 of the yoke. Coil 35 is `formed of 7 turns of No. I12 wire insulated. A stiff, resilient material such as bakelite or hard rubber isV preferably used in the switch base i to give the rebound to the armature and to magnify the sound made by the hammering of the armature onthe switch base.

The solenoid action of the core on the parts which move the contact 43 is produced by the magnetic flux passing-from the core 26 through the air gap tothe soft iron 'disc 33, then dividing and passing through the v yoke arms 21, 22 back to thecore. y

y During normal operation of the electrical system the current owing throughthe circuitbreaking relay is too small to operate the latter. When a short is -formedin -the circuit the currentis increased and the relay. 1. operates. The armature or disc 33 is moved towardpthe core.. This irst movement l"is relatively slow due 'chiel-ly to the mass of metal to be moved and to the inductance'bf the solenoid unit. The contacts 41, 43 are .separated just beforefthe armature engages the core,.this separation breaking the/cur- 'rent liowing from the battery throggh the coil 36, contacts y41, 43, spring 42, yoke* 20 and binding post 18,to the short in the circuit...v The sprlng thentends to move the members28and 33 toward their initial positions but this downward movement is delayed 'by the' following causes: rst, the'upwardly moving hea armature 33 must be reversed in itsdirections yo;tmove'ment; second, the gap between armature 33 and core 26 is a minimum and hence the reluctancevof the magnetic.v circuit is. also a minimum when contacts 41 and 43- are open; ltherefore the inductance-of the solenoid unit Ais a maxiv mum at this time and hence the magnetic flux in the iron-path dies out quite slowlyI after contacts 41 and 43 are broken. Therefore it will be obvious lthat armature '33 will tend to stick for ashort'/ interval of time at the top of its stroke. The contacts 41, 43 close during the first part of the movement permitting a current iow through the coil* but the Ibuilding up of this 'current is de-' layed by the eddy currentsin thel copper r f sleeve 34 which currents redu'ce the. rate of change of magneticpiiuX in the core. Thisv avoids a rapid operation 'of the movable contact and` reduces the current consumption. In the specific examplegiven, the, armature is returned to its initial position with suiiciept, force to strike the base plate 11 of the switch box, the. rebound of the armature in itia'ting its movement in the opposite direction and Jfurther reducing the current re vquired to .operatethe circuit breaking relay.' When the horn is sounded the initial rush of current to the horn added to the normal current used maybe large enough to oper- Q ate the relayv but the operation of the relay is so sluggishthat the time of the initial high current How is usually too. short to' start the relay. y f

Thehammering of the armature against Vthe base plate -is magnified by the' switch .ment with the plunger; ai spring. arm secured to the magnet frame; and a contact button carriedfby the spring arm and held in yieldable 'engagement with `the stationary contact.

i 2. A circuit controlling-relay, comprising in combination, a base; a .C-shaped magnet frame including an end portion and `parallel arms, said frame being securedto the base so as to have the end of saidarms engaging said base; a hollow core secured to the end portion of magnet so as to be intermediate thefarms of said "frame, the end of said core being in spaced relations tothe base; a.

plunger` in said core one end YJof which eX'-L tends through and beyond the end portion of fthe frame; an armature disc securedto the 'other end of the plunger on said disc normally resting on the base'and being in spaced relation to the`end of the core when the relay is inoperable; an annular shaped Icontact mounted on but insulated from the end portion of' the frame 'so as to surround the' end of the plunger extending 'from said frame; and a movablev contact yieldingly held inengagementwith the annular shaped v contact and adapted to be engaged by the plunger when the magnet-is energized; said plunger striking the base and permitting the movablecontact. to engage the magnet con- K tact when the magnet '1s de-energized.

u 3. A circuit controlling relay comprising in combination, a base a C-shap'ed frame including an endwportion and parallel arms, one ofthe said arms having a foot bymeans ofwhich said frame isy secured to the base so that .the other army will engage said base; a stationary contact in the form of an annulus carried by and insulated from the end portion of thev frame; a spring arm secured' to one arm of the' framegJa movable contact carried by said spring arm and held in yieldable engagement with theC stationary contact; a hollow core secured to the end portion of the frame so as to. be `co`axial with the annular contact,"the said core being substantially shorter than the arm of the frame thereby providing a space between the end of the core and the base; a plunger in said c ore having its one end extending through the frame and into the annular contact member so that the end of plunger is substantially below the outer surface of said contact when the magnet is inoperative whereby to provide a space between the end of plunger and the stationary contact member; an armature disc carried by the plunger, said disc engaging the base and being spaced from the end of the core when the magnet is inoperative; and a spring in yieldable engagement with and holding the said plunger in said normal position, said spring being adapted to cause the armature to strike the base when said armature is returned to normal position after the magnet has been de-energized.

4. A circuit controller comprising, in combination, a base, a tubular magnet core, a frame attached to the base and supporting the core at right angles to the base and spaced therefrom, an armature for striking the base located between the core and base, a plunger extending through the core and carrying the armature at one end of the plunger, a stationary Contact supported by the frame and having an aperture for receiving the other end of the plunger, a movable contact yieldingly urged against the stationary contact and en aged by the plunger in order to separate it rom the stationary contact, and a magnet coil surrounding the coil and connected with one of the contacts.

5. A circuit controller comprising, in combination, a base, a tubular magnet core, a magnet frame 'attached to the base and supporting the core at right angles to the base and spaced therefrom, an armature for strikingy the base located between the core and the base, a plunger extending through the core and carrying the armature at one end of the plunger, a circuit breaker carried by the frame and operated by the other end of the plunger, said circuit breaker having a contact electrically connected with the frame, a magnet coil electrically connected Withthe other contact andsurrounding the core, and a spring within the core for moving the plunger in such direction as to cause the armature to strike the base, and to move the plunger away from the circuit breaker to permlt its contacts to close.

In testimony whereof I hereto aflix my signature.

NELSON R. HAAS. 

